Adaptive multipath tunneling in cloud-based systems

ABSTRACT

Systems and methods implemented by a mobile device include establishing a plurality of tunnels to a gateway, wherein each of the plurality of tunnels is on one of a plurality of link layer channels at the mobile device; intercepting network traffic on the mobile device; forwarding the network traffic to one of the plurality of tunnels based on a set of traffic forwarding rules; and responsive to a network change for the mobile device, managing the plurality of tunnels and continuing the forwarding based on the managing. The systems and methods can further include determining characteristics including bandwidth of each of the plurality of link layer channels; and utilizing the characteristics with the set of traffic forwarding rules for the forwarding.

CROSS-REFERENCE TO RELATED APPLICATION(S)

The present patent application/patent is a continuation-in-part of U.S.patent application Ser. No. 16/922,353, filed Jul. 7, 2020, and entitled“Enforcing security policies on mobile devices in a hybridarchitecture,” which claims the benefit of priority of Indian PatentApplication No. 202011021372, filed on May 21, 2020, and entitled“Enforcing security policies on mobile devices in a hybridarchitecture,” the contents of each are incorporated by reference hereinin their entirety.

Also, the present patent application/patent is a continuation-in-part ofU.S. patent application Ser. No. 15/900,951, filed Feb. 21, 2018, andentitled “SYSTEMS AND METHODS FOR CLOUD BASED UNIFIED SERVICE DISCOVERYAND SECURE AVAILABILITY,” which is a continuation of U.S. patentapplication Ser. No. 15/153,108, filed May 12, 2016 (now U.S. Pat. No.9,935,955, issued Apr. 3, 2018) and entitled “SYSTEMS AND METHODS FORCLOUD BASED UNIFIED SERVICE DISCOVERY AND SECURE AVAILABILITY,” whichclaims the benefit of priority of Indian Patent Application No.201611010521, filed on Mar. 28, 2016, and entitled “SYSTEMS AND METHODSFOR CLOUD BASED UNIFIED SERVICE DISCOVERY AND SECURE AVAILABILITY,” thecontents of each are incorporated by reference herein in their entirety.

FIELD OF THE DISCLOSURE

The present disclosure generally relates to computer networking systemsand methods. More particularly, the present disclosure relates tosystems and methods for adaptive multipath tunneling in cloud-basedsystems.

BACKGROUND OF THE DISCLOSURE

There has been an explosive growth of mobile device usage inenterprises. Traditionally enterprises deployed Secure Sockets Layer(SSL)/Internet Protocol (IP) Security (IPSec) Virtual Private Networks(VPNs)/proxies to steer traffic from mobile devices to a centralized,secure gateway which was used to provide resource access to users inaddition to performing various cloud-based functions, e.g., webfiltering, security scans, Data Loss Prevention (DLP), etc., on thenetwork traffic for policy compliance and protection from malware. Overthe years, as more and more people have started working from home, thisbackhauling all of all user traffic from a mobile device to thecentralized gateway has caused a serious performance and scalabilitychallenges. Further, mobile devices have limited resources and operateunder several constraints, such as battery utilization that makestraditional SSL and IPSec VPN solutions expensive to operate. Usually,mobile devices can hop quickly from one network to another, such asbetween cellular and Wi-Fi that quite often require the whole VPN tunnelto tear down and get reestablished again, which often causes loss ofnetwork access resulting in bad user experience. This is hugelyinefficient in terms of server and client processing power as it wastesa lot of resources to reestablish secure network connectivity.

BRIEF SUMMARY OF THE DISCLOSURE

The present disclosure relates to systems and methods for adaptivemultipath tunneling in cloud-based systems. Specifically, the presentdisclosure describes a performance-based adaptive multipath tunnelingsolution for mobile devices to connect to cloud-based systems, such asfor security, secure application access, etc. The tunnels areestablished independently on multiple available paths to maximizeresource usage and increase redundancy. This solution is inspired bymultipath Transmission Control Protocol (TCP) (RFC 6824, “TCP Extensionsfor Multipath Operation with Multiple Address,” January 2013, thecontents of which are incorporated by reference) and applies theprinciples of using multiple channels for communication for VPN tunnelswithout relying on the multipath TCP original design of splitting TCPcommunication flow between client and server applications over multiplechannels that usually suffers from issues with Network AddressTranslation (NAT) traversals and network scanning devices. The adaptivemultipath tunneling supports increased throughput to the sum of allavailable link-level channels, support for prioritized network trafficand preemption, fault tolerance, and compatibility with existingnetworking devices.

In various embodiments, the present disclosure includes a method withsteps, a mobile device node configured to implement the steps, and anon-transitory computer-readable medium storing computer-executableinstructions for causing performance of the steps on a mobile device.The steps include establishing a plurality of tunnels to a gateway,wherein each of the plurality of tunnels is on one of a plurality oflink layer channels at the mobile device; intercepting network trafficon the mobile device; forwarding the network traffic to one of theplurality of tunnels based on a set of traffic forwarding rules; andresponsive to a network change for the mobile device, managing theplurality of tunnels and continuing the forwarding based on themanaging. The steps can further include determining characteristicsincluding bandwidth of each of the plurality of link layer channels; andutilizing the characteristics with the set of traffic forwarding rulesfor the forwarding. The steps can further include configuring theapplication with the set of traffic forwarding rules. The set of trafficforwarding rules can include a tuple of address or domain, assignedpriority, and address of the gateway. Each of the plurality of tunnelscan be a lightweight tunnel that is Hypertext Transfer Protocol(HTTP)-based. The intercepting can be via one of a virtual interface anda network filter. The plurality of link layer channels can include awireless cellular channel and a Wi-Fi channel. The managing can includeadding or removing tunnels based the network change. The forwarding caninclude forwarding traffic to all of the plurality of tunnelsconcurrently.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure is illustrated and described herein withreference to the various drawings, in which like reference numbers areused to denote like system components/method steps, as appropriate, andin which:

FIG. 1 is a network diagram of a cloud-based system offering security asa service;

FIG. 2 is a network diagram of an example implementation of thecloud-based system;

FIG. 3 is a block diagram of a server that may be used in thecloud-based system of FIGS. 1 and 2 or the like;

FIG. 4 is a block diagram of a user device that may be used with thecloud-based system of FIGS. 1 and 2 or the like;

FIG. 5 is a network diagram of the cloud-based system illustrating anapplication on user devices with users configured to operate through thecloud-based system;

FIG. 6 is a network diagram of a Zero Trust Network Access (ZTNA)application utilizing the cloud-based system of FIGS. 1 and 2;

FIG. 7 is a network diagram of the cloud-based system of FIGS. 1 and 2in an application of digital experience monitoring;

FIG. 8 is a network diagram of a unified agent application andassociated connectivity and functionality with the cloud-based system;

FIG. 9 is a network diagram of example workflow of the unified agentapplication;

FIG. 10 is a flow diagram of an event sequence associated with theunified agent application;

FIG. 11 is a logical diagram of functional components of the unifiedagent application;

FIG. 12 is a flowchart of a proxy authentication process to thecloud-based system;

FIG. 13 is a flowchart of a VPN authentication process to thecloud-based system;

FIG. 14 is a flowchart of a device enrollment process for the clientuser device and the unified agent application;

FIG. 15 is a flowchart of a traffic interception process implementedthrough the unified agent application;

FIG. 16 is a flow diagram of traffic interception and splitting usingthe unified agent application;

FIG. 17 is a flow diagram of tunnel forwarding rules by the unifiedagent application;

FIG. 18 is a flowchart of a service drive split tunneling process;

FIG. 19 is a flowchart of a process for security processing in a hybridarchitecture; and

FIG. 20 is a flowchart of a process for adaptive multipath trafficforwarding.

DETAILED DESCRIPTION OF THE DISCLOSURE

Again, the present disclosure relates to systems and methods foradaptive multipath tunneling in cloud-based systems. Specifically, thepresent disclosure describes a performance-based adaptive multipathtunneling solution for mobile devices to connect to cloud-based systems,such as for security, secure application access, etc. The tunnels areestablished independently on multiple available paths to maximizeresource usage and increase redundancy. This solution is inspired bymultipath Transmission Control Protocol (TCP) (RFC 6824, “TCP Extensionsfor Multipath Operation with Multiple Address,” January 2013, thecontents of which are incorporated by reference) and applies theprinciples of using multiple channels for communication for VPN tunnelswithout relying on the multipath TCP original design of splitting TCPcommunication flow between client and server applications over multiplechannels that usually suffers from issues with Network AddressTranslation (NAT) traversals and network scanning devices. The adaptivemultipath tunneling supports increased throughput to the sum of allavailable link-level channels, support for prioritized network trafficand preemption, fault tolerance, and compatibility with existingnetworking devices.

Additionally, the present disclosure relates to systems and methods forservice-driven split tunneling of mobile network traffic. The systemsand methods include an app or agent on a user device (e.g., a mobiledevice) which performs split tunneling based upon port, protocol, anddestination IP address instead of just destination IP. This providesgranular controls to IT administrators to steer a user's network trafficbased upon the demands of the service. This is very advantageous from ascalability point of view as the demands for a particular service grow,that traffic can be individually distributed, load-balanced, and servedwithout impacting traffic of other services. This form of splittunneling also allows for efficient usage of resources both on the enduser's device as well as backend concentrators. For instance, if alltraffic, including Hypertext Transfer Protocol (HTTP) and HTTP Secure(HTTPS), is tunneled via an SSL VPN, there is an overhead of decryptingSSL traffic twice, one for the transport and the other for theapplication itself. While splitting traffic based upon the protocol, theHTTPS transport can go unencrypted since the HTTPS traffic itself isencrypted. This saves both the client and the avoiding encryption anddecryption twice, saving a significant amount of computational power onall ends.

Another benefit of this form of split tunneling is that it takes intoaccount the quality of service requirements for different protocols. Forexample, in a conventional VPN, all VOIP and UDP traffic will betunneled over an SSL VPN with all other TCP traffic as well. Since allthese protocols have different service requirements, the traditional VPNgenerally underperforms and is difficult to scale. With thisservice-driven split tunneling, VOIP over UDP traffic can be tunneledseparately to a specific UDP traffic concentrator that is designed forhandling large volumes of such traffic. In this case, VOIP traffic doesnot need to fight with other protocols through its intended destination.In another use case, an admin may altogether decide not to tunnel VOIPtraffic and go directly from the user's device. Note that this kind ofgranularity is not possible with split tunneling based upon destinationIP address alone. The service-driven split tunneling further allows foron-demand embarking (or disembarking) of particular network traffic,i.e., whenever the IT infrastructure is ready to support a new protocol,the agent can start (or stop) tunneling that traffic based upon theconfigured rules.

Further, the present disclosure relates to systems and methods forcloud-based unified service discovery and secure availability. Thesystems and methods enable a user to connect to multiple cloud servicesthrough the dynamic discovery of available services, followed byauthentication and access as exposed in the corresponding serviceprotocol. The systems and methods address the unmanageable growth ofmobility and cloud-based services, which have led to a proliferation ofindividual applications for access to individual services. The systemsand method can be implemented through a mobile application (“app”),which overcomes the hassle of deploying and managing severalapplications across a gamut of mobile devices, operating systems, andmobile networks to gain secure access to the cloud-based Internet orintranet resources. The mobile application can uniquely perform aDynamic evaluation of Network and Service Discovery, Unified Enrollmentto all services, application-dependent service enablement, Serviceprotocol learning, Service Availability through secure network trafficforwarding tunnels, and the like.

Again, enterprises have a strong need to provide secure access to cloudservices to its end users. The growth of mobility and cloud in the ITenterprise has made it impossible for IT admins to deploy individualapplications for individual services. The mobile app associated with thesystems and methods overcomes these limitations through the dynamicdiscovery of available services to the end user, followed byauthentication and access to individual services. Further, the mobileapp insightfully learns the protocol for each service and establishes asecure tunnel to the service. In essence, the mobile app is one app thatan enterprise may use to provide secure connectivity to the Internet anddiversified internal corporate applications. At the time of userenrollment, the mobile app will discover all services provided by theenterprise cloud and will enroll the user in all of those services. Itwill then set up secure tunnels for each service depending upon theport, protocol, and intended destination of requested traffic.

The mobile app will also discover all applications provided within theenterprise cloud along with a Global VPN (GVPN) service and show theavailable services to end users. Endpoint Applications today provide oneservice for a specific network function (such as a VPN to a corporatenetwork, web security, antivirus to access the Internet). The mobile appcan be used to enable all these services with single enrollment. Themobile app will provide services to darknet applications along withsecuring the Internet traffic. The mobile app can set up a local networkon the mobile device.

Example Cloud-Based System Architecture

FIG. 1 is a network diagram of a cloud-based system 100 offeringsecurity as a service. Specifically, the cloud-based system 100 canoffer a Secure Internet and Web Gateway as a service to various users102, as well as other cloud services. In this manner, the cloud-basedsystem 100 is located between the users 102 and the Internet as well asany cloud services 106 (or applications) accessed by the users 102. Assuch, the cloud-based system 100 provides inline monitoring inspectingtraffic between the users 102, the Internet 104, and the cloud services106, including Secure Sockets Layer (SSL) traffic. The cloud-basedsystem 100 can offer access control, threat prevention, data protection,etc. The access control can include a cloud-based firewall, cloud-basedintrusion detection, Uniform Resource Locator (URL) filtering, bandwidthcontrol, Domain Name System (DNS) filtering, etc. The threat preventioncan include cloud-based intrusion prevention, protection againstadvanced threats (malware, spam, Cross-Site Scripting (XSS), phishing,etc.), cloud-based sandbox, antivirus, DNS security, etc. The dataprotection can include Data Loss Prevention (DLP), cloud applicationsecurity such as via Cloud Access Security Broker (CASB), file typecontrol, etc.

The cloud-based firewall can provide Deep Packet Inspection (DPI) andaccess controls across various ports and protocols as well as beingapplication and user aware. The URL filtering can block, allow, or limitwebsite access based on policy for a user, group of users, or entireorganization, including specific destinations or categories of URLs(e.g., gambling, social media, etc.). The bandwidth control can enforcebandwidth policies and prioritize critical applications such as relativeto recreational traffic. DNS filtering can control and block DNSrequests against known and malicious destinations.

The cloud-based intrusion prevention and advanced threat protection candeliver full threat protection against malicious content such as browserexploits, scripts, identified botnets and malware callbacks, etc. Thecloud-based sandbox can block zero-day exploits (just identified) byanalyzing unknown files for malicious behavior. Advantageously, thecloud-based system 100 is multi-tenant and can service a large volume ofthe users 102. As such, newly discovered threats can be promulgatedthroughout the cloud-based system 100 for all tenants practicallyinstantaneously. The antivirus protection can include antivirus,antispyware, antimalware, etc. protection for the users 102, usingsignatures sourced and constantly updated. The DNS security can identifyand route command-and-control connections to threat detection enginesfor full content inspection.

The DLP can use standard and/or custom dictionaries to continuouslymonitor the users 102, including compressed and/or SSL-encryptedtraffic. Again, being in a cloud implementation, the cloud-based system100 can scale this monitoring with near-zero latency on the users 102.The cloud application security can include CASB functionality todiscover and control user access to known and unknown cloud services106. The file type controls enable true file type control by the user,location, destination, etc. to determine which files are allowed or not.

For illustration purposes, the users 102 of the cloud-based system 100can include a mobile device 110, a headquarters (HQ) 112 which caninclude or connect to a data center (DC) 114, Internet of Things (IoT)devices 116, a branch office/remote location 118, etc., and eachincludes one or more user devices (an example user device 300 isillustrated in FIG. 3). The devices 110, 116, and the locations 112,114, 118 are shown for illustrative purposes, and those skilled in theart will recognize there are various access scenarios and other users102 for the cloud-based system 100, all of which are contemplatedherein. The users 102 can be associated with a tenant, which may includean enterprise, a corporation, an organization, etc. That is, a tenant isa group of users who share a common access with specific privileges tothe cloud-based system 100, a cloud service, etc. In an embodiment, theheadquarters 112 can include an enterprise's network with resources inthe data center 114. The mobile device 110 can be a so-called roadwarrior, i.e., users that are off-site, on-the-road, etc.

Further, the cloud-based system 100 can be multi-tenant, with eachtenant having its own users 102 and configuration, policy, rules, etc.One advantage of the multi-tenancy and a large volume of users is thezero-day/zero-hour protection in that a new vulnerability can bedetected and then instantly remediated across the entire cloud-basedsystem 100. The same applies to policy, rule, configuration, etc.changes—they are instantly remediated across the entire cloud-basedsystem 100. As well, new features in the cloud-based system 100 can alsobe rolled up simultaneously across the user base, as opposed toselective and time-consuming upgrades on every device at the locations112, 114, 118, and the devices 110, 116.

Logically, the cloud-based system 100 can be viewed as an overlaynetwork between users (at the locations 112, 114, 118, and the devices110, 116) and the Internet 104 and the cloud services 106. Previously,the IT deployment model included enterprise resources and applicationsstored within the data center 114 (i.e., physical devices) behind afirewall (perimeter), accessible by employees, partners, contractors,etc. on-site or remote via Virtual Private Networks (VPNs), etc. Thecloud-based system 100 is replacing the conventional deployment model.The cloud-based system 100 can be used to implement these services inthe cloud without requiring the physical devices and management thereofby enterprise IT administrators. As an ever-present overlay network, thecloud-based system 100 can provide the same functions as the physicaldevices and/or appliances regardless of geography or location of theusers 102, as well as independent of platform, operating system, networkaccess technique, network access provider, etc.

There are various techniques to forward traffic between the users 102 atthe locations 112, 114, 118, and via the devices 110, 116, and thecloud-based system 100. Typically, the locations 112, 114, 118, can usetunneling where all traffic is forward through the cloud-based system100. For example, various tunneling protocols are contemplated, such asGeneric Routing Encapsulation (GRE), Layer Two Tunneling Protocol(L2TP), Internet Protocol (IP) Security (IPsec), customized tunnelingprotocols, etc. The devices 110, 116, when not at one of the locations112, 114, 118, can use a local application that forwards traffic, aproxy such as via a Proxy Auto-Config (PAC) file, and the like. A keyaspect of the cloud-based system 100 is all traffic between the users102 and the Internet 104 or the cloud services 106 is via thecloud-based system 100. As such, the cloud-based system 100 hasvisibility to enable various functions, all of which are performed offthe user device in the cloud.

The cloud-based system 100 can also include a management system 120 fortenant access to provide global policy and configuration as well asreal-time analytics. This enables IT administrators to have a unifiedview of user activity, threat intelligence, application usage, etc. Forexample, IT administrators can drill-down to a per-user level tounderstand events and correlate threats, to identify compromiseddevices, to have application visibility, and the like. The cloud-basedsystem 100 can further include connectivity to an Identity Provider(IDP) 122 for authentication of the users 102 and to a SecurityInformation and Event Management (SIEM) system 124 for event logging.The system 124 can provide alert and activity logs on a per-user 102basis.

FIG. 2 is a network diagram of an example implementation of thecloud-based system 100. In an embodiment, the cloud-based system 100includes a plurality of enforcement nodes (EN) 150, labeled asenforcement nodes 150-1, 150-2, 150-N, interconnected to one another andinterconnected to a central authority (CA) 152. The nodes 150, 152,while described as nodes, can include one or more servers, includingphysical servers, virtual machines (VM) executed on physical hardware,etc. An example of a server is illustrated in FIG. 2. The cloud-basedsystem 100 further includes a log router 154 that connects to a storagecluster 156 for supporting log maintenance from the enforcement nodes150. The central authority 152 provide centralized policy, real-timethreat updates, etc. and coordinates the distribution of this databetween the enforcement nodes 150. The enforcement nodes 150 provide anonramp to the users 102 and are configured to execute policy, based onthe central authority 152, for each user 102. The enforcement nodes 150can be geographically distributed, and the policy for each user 102follows that user 102 as he or she connects to the nearest (or othercriteria) enforcement node 150. Of note, the cloud-based system is anexternal system meaning it is separate from tenant's private networks(enterprise networks) as well as from networks associated with thedevices 110, 116, and locations 112, 118.

The enforcement nodes 150 are full-featured secure internet gatewaysthat provide integrated internet security. They inspect all web trafficbi-directionally for malware and enforce security, compliance, andfirewall policies, as described herein. In an embodiment, eachenforcement node 150 has two main modules for inspecting traffic andapplying policies: a web module and a firewall module. The enforcementnodes 150 are deployed around the world and can handle hundreds ofthousands of concurrent users with millions of concurrent sessions.Because of this, regardless of where the users 102 are, they can accessthe Internet 104 from any device, and the enforcement nodes 150 protectthe traffic and apply corporate policies. The enforcement nodes 150 canimplement various inspection engines therein, and optionally, sendsandboxing to another system. The enforcement nodes 150 includesignificant fault tolerance capabilities, such as deployment inactive-active mode to ensure availability and redundancy as well ascontinuous monitoring.

In an embodiment, customer traffic is not passed to any other componentwithin the cloud-based system 100, and the enforcement nodes 150 can beconfigured never to store any data to disk. Packet data is held inmemory for inspection and then, based on policy, is either forwarded ordropped. Log data generated for every transaction is compressed,tokenized, and exported over secure TLS connections to the log routers154 that direct the logs to the storage cluster 156, hosted in theappropriate geographical region, for each organization. In anembodiment, all data destined for or received from the Internet isprocessed through one of the enforcement nodes 150. In anotherembodiment, specific data specified by each tenant, e.g., only email,only executable files, etc., is process through one of the enforcementnodes 150.

Each of the enforcement nodes 150 may generate a decision vector D=[d1,d2, . . . , dn] for a content item of one or more parts C=[c1, c2, . . ., cm]. Each decision vector may identify a threat classification, e.g.,clean, spyware, malware, undesirable content, innocuous, spam email,unknown, etc. For example, the output of each element of the decisionvector D may be based on the output of one or more data inspectionengines. In an embodiment, the threat classification may be reduced to asubset of categories, e.g., violating, non-violating, neutral, unknown.Based on the subset classification, the enforcement node 150 may allowthe distribution of the content item, preclude distribution of thecontent item, allow distribution of the content item after a cleaningprocess, or perform threat detection on the content item. In anembodiment, the actions taken by one of the enforcement nodes 150 may bedeterminative on the threat classification of the content item and on asecurity policy of the tenant to which the content item is being sentfrom or from which the content item is being requested by. A contentitem is violating if, for any part C=[c1, c2, . . . , cm] of the contentitem, at any of the enforcement nodes 150, any one of the datainspection engines generates an output that results in a classificationof “violating.”

The central authority 152 hosts all customer (tenant) policy andconfiguration settings. It monitors the cloud and provides a centrallocation for software and database updates and threat intelligence.Given the multi-tenant architecture, the central authority 152 isredundant and backed up in multiple different data centers. Theenforcement nodes 150 establish persistent connections to the centralauthority 152 to download all policy configurations. When a new userconnects to an enforcement node 150, a policy request is sent to thecentral authority 152 through this connection. The central authority 152then calculates the policies that apply to that user 102 and sends thepolicy to the enforcement node 150 as a highly compressed bitmap.

The policy can be tenant-specific and can include access privileges forusers, websites and/or content that is disallowed, restricted domains,DLP dictionaries, etc. Once downloaded, a tenant's policy is cacheduntil a policy change is made in the management system 120. The policycan be tenant-specific and can include access privileges for users,websites and/or content that is disallowed, restricted domains, DLPdictionaries, etc. When this happens, all of the cached policies arepurged, and the enforcement nodes 150 request the new policy when theuser 102 next makes a request. In an embodiment, the enforcement node150 exchange “heartbeats” periodically, so all enforcement nodes 150 areinformed when there is a policy change. Any enforcement node 150 canthen pull the change in policy when it sees a new request.

The cloud-based system 100 can be a private cloud, a public cloud, acombination of a private cloud and a public cloud (hybrid cloud), or thelike. Cloud computing systems and methods abstract away physicalservers, storage, networking, etc., and instead offer these as on-demandand elastic resources. The National Institute of Standards andTechnology (NIST) provides a concise and specific definition whichstates cloud computing is a model for enabling convenient, on-demandnetwork access to a shared pool of configurable computing resources(e.g., networks, servers, storage, applications, and services) that canbe rapidly provisioned and released with minimal management effort orservice provider interaction. Cloud computing differs from the classicclient-server model by providing applications from a server that areexecuted and managed by a client's web browser or the like, with noinstalled client version of an application required. Centralizationgives cloud service providers complete control over the versions of thebrowser-based and other applications provided to clients, which removesthe need for version upgrades or license management on individual clientcomputing devices. The phrase “Software as a Service” (SaaS) issometimes used to describe application programs offered through cloudcomputing. A common shorthand for a provided cloud computing service (oreven an aggregation of all existing cloud services) is “the cloud.” Thecloud-based system 100 is illustrated herein as an example embodiment ofa cloud-based system, and other implementations are also contemplated.

As described herein, the terms cloud services and cloud applications maybe used interchangeably. The cloud service 106 is any service madeavailable to users on-demand via the Internet, as opposed to beingprovided from a company's on-premises servers. A cloud application, orcloud app, is a software program where cloud-based and local componentswork together. The cloud-based system 100 can be utilized to provideexample cloud services, including Zscaler Internet Access (ZIA), ZscalerPrivate Access (ZPA), and Zscaler Digital Experience (ZDX), all fromZscaler, Inc. (the assignee and applicant of the present application).The ZIA service can provide the access control, threat prevention, anddata protection described above with reference to the cloud-based system100. ZPA can include access control, microservice segmentation, etc. TheZDX service can provide monitoring of user experience, e.g., Quality ofExperience (QoE), Quality of Service (QoS), etc., in a manner that cangain insights based on continuous, inline monitoring. For example, theZIA service can provide a user with Internet Access, and the ZPA servicecan provide a user with access to enterprise resources instead oftraditional Virtual Private Networks (VPNs), namely ZPA provides ZeroTrust Network Access (ZTNA). Those of ordinary skill in the art willrecognize various other types of cloud services 106 are alsocontemplated. Also, other types of cloud architectures are alsocontemplated, with the cloud-based system 100 presented for illustrationpurposes.

Example Server Architecture

FIG. 3 is a block diagram of a server 200, which may be used in thecloud-based system 100, in other systems, or standalone. For example,the enforcement nodes 150 and the central authority 152 may be formed asone or more of the servers 200. The server 200 may be a digital computerthat, in terms of hardware architecture, generally includes a processor202, input/output (I/O) interfaces 204, a network interface 206, a datastore 208, and memory 210. It should be appreciated by those of ordinaryskill in the art that FIG. 3 depicts the server 200 in an oversimplifiedmanner, and a practical embodiment may include additional components andsuitably configured processing logic to support known or conventionaloperating features that are not described in detail herein. Thecomponents (202, 204, 206, 208, and 210) are communicatively coupled viaa local interface 212. The local interface 212 may be, for example, butnot limited to, one or more buses or other wired or wirelessconnections, as is known in the art. The local interface 212 may haveadditional elements, which are omitted for simplicity, such ascontrollers, buffers (caches), drivers, repeaters, and receivers, amongmany others, to enable communications. Further, the local interface 212may include address, control, and/or data connections to enableappropriate communications among the aforementioned components.

The processor 202 is a hardware device for executing softwareinstructions. The processor 202 may be any custom made or commerciallyavailable processor, a Central Processing Unit (CPU), an auxiliaryprocessor among several processors associated with the server 200, asemiconductor-based microprocessor (in the form of a microchip orchipset), or generally any device for executing software instructions.When the server 200 is in operation, the processor 202 is configured toexecute software stored within the memory 210, to communicate data toand from the memory 210, and to generally control operations of theserver 200 pursuant to the software instructions. The I/O interfaces 204may be used to receive user input from and/or for providing systemoutput to one or more devices or components.

The network interface 206 may be used to enable the server 200 tocommunicate on a network, such as the Internet 104. The networkinterface 206 may include, for example, an Ethernet card or adapter or aWireless Local Area Network (WLAN) card or adapter. The networkinterface 206 may include address, control, and/or data connections toenable appropriate communications on the network. A data store 208 maybe used to store data. The data store 208 may include any of volatilememory elements (e.g., random access memory (RAM, such as DRAM, SRAM,SDRAM, and the like)), nonvolatile memory elements (e.g., ROM, harddrive, tape, CDROM, and the like), and combinations thereof.

Moreover, the data store 208 may incorporate electronic, magnetic,optical, and/or other types of storage media. In one example, the datastore 208 may be located internal to the server 200, such as, forexample, an internal hard drive connected to the local interface 212 inthe server 200. Additionally, in another embodiment, the data store 208may be located external to the server 200 such as, for example, anexternal hard drive connected to the I/O interfaces 204 (e.g., SCSI orUSB connection). In a further embodiment, the data store 208 may beconnected to the server 200 through a network, such as, for example, anetwork-attached file server.

The memory 210 may include any of volatile memory elements (e.g., randomaccess memory (RAM, such as DRAM, SRAM, SDRAM, etc.)), nonvolatilememory elements (e.g., ROM, hard drive, tape, CDROM, etc.), andcombinations thereof. Moreover, the memory 210 may incorporateelectronic, magnetic, optical, and/or other types of storage media. Notethat the memory 210 may have a distributed architecture, where variouscomponents are situated remotely from one another but can be accessed bythe processor 202. The software in memory 210 may include one or moresoftware programs, each of which includes an ordered listing ofexecutable instructions for implementing logical functions. The softwarein the memory 210 includes a suitable Operating System (O/S) 214 and oneor more programs 216. The operating system 214 essentially controls theexecution of other computer programs, such as the one or more programs216, and provides scheduling, input-output control, file and datamanagement, memory management, and communication control and relatedservices. The one or more programs 216 may be configured to implementthe various processes, algorithms, methods, techniques, etc. describedherein.

Example User Device Architecture

FIG. 4 is a block diagram of a user device 300, which may be used withthe cloud-based system 100 or the like. Specifically, the user device300 can form a device used by one of the users 102, and this may includecommon devices such as laptops, smartphones, tablets, netbooks, personaldigital assistants, MP3 players, cell phones, e-book readers, IoTdevices, servers, desktops, printers, televisions, streaming mediadevices, and the like. The user device 300 can be a digital device that,in terms of hardware architecture, generally includes a processor 302,I/O interfaces 304, a network interface 306, a data store 308, andmemory 310. It should be appreciated by those of ordinary skill in theart that FIG. 4 depicts the user device 300 in an oversimplified manner,and a practical embodiment may include additional components andsuitably configured processing logic to support known or conventionaloperating features that are not described in detail herein. Thecomponents (302, 304, 306, 308, and 302) are communicatively coupled viaa local interface 312. The local interface 312 can be, for example, butnot limited to, one or more buses or other wired or wirelessconnections, as is known in the art. The local interface 312 can haveadditional elements, which are omitted for simplicity, such ascontrollers, buffers (caches), drivers, repeaters, and receivers, amongmany others, to enable communications. Further, the local interface 312may include address, control, and/or data connections to enableappropriate communications among the aforementioned components.

The processor 302 is a hardware device for executing softwareinstructions. The processor 302 can be any custom made or commerciallyavailable processor, a CPU, an auxiliary processor among severalprocessors associated with the user device 300, a semiconductor-basedmicroprocessor (in the form of a microchip or chipset), or generally anydevice for executing software instructions. When the user device 300 isin operation, the processor 302 is configured to execute software storedwithin the memory 310, to communicate data to and from the memory 310,and to generally control operations of the user device 300 pursuant tothe software instructions. In an embodiment, the processor 302 mayinclude a mobile-optimized processor such as optimized for powerconsumption and mobile applications. The I/O interfaces 304 can be usedto receive user input from and/or for providing system output. Userinput can be provided via, for example, a keypad, a touch screen, ascroll ball, a scroll bar, buttons, a barcode scanner, and the like.System output can be provided via a display device such as a LiquidCrystal Display (LCD), touch screen, and the like.

The network interface 306 enables wireless communication to an externalaccess device or network. Any number of suitable wireless datacommunication protocols, techniques, or methodologies can be supportedby the network interface 306, including any protocols for wirelesscommunication. The data store 308 may be used to store data. The datastore 308 may include any of volatile memory elements (e.g., randomaccess memory (RAM, such as DRAM, SRAM, SDRAM, and the like)),nonvolatile memory elements (e.g., ROM, hard drive, tape, CDROM, and thelike), and combinations thereof. Moreover, the data store 308 mayincorporate electronic, magnetic, optical, and/or other types of storagemedia.

The memory 310 may include any of volatile memory elements (e.g., randomaccess memory (RAM, such as DRAM, SRAM, SDRAM, etc.)), nonvolatilememory elements (e.g., ROM, hard drive, etc.), and combinations thereof.Moreover, the memory 310 may incorporate electronic, magnetic, optical,and/or other types of storage media. Note that the memory 310 may have adistributed architecture, where various components are situated remotelyfrom one another but can be accessed by the processor 302. The softwarein memory 310 can include one or more software programs, each of whichincludes an ordered listing of executable instructions for implementinglogical functions. In the example of FIG. 3, the software in the memory310 includes a suitable operating system 314 and programs 316. Theoperating system 314 essentially controls the execution of othercomputer programs and provides scheduling, input-output control, fileand data management, memory management, and communication control andrelated services. The programs 316 may include various applications,add-ons, etc. configured to provide end-user functionality with the userdevice 300. For example, example programs 316 may include, but notlimited to, a web browser, social networking applications, streamingmedia applications, games, mapping and location applications, electronicmail applications, financial applications, and the like. In a typicalexample, the end-user typically uses one or more of the programs 316along with a network such as the cloud-based system 100.

The present disclosure relates to mobile devices, which are one subsetof the user device 300. Specifically, the user device 300 as a mobiledevice can change network connectivity periodically, e.g., switchingbetween cellular and Wi-Fi, and the mobile device has processinglimitations, mainly due to battery optimization.

User Device Application for Traffic Forwarding and Monitoring

FIG. 5 is a network diagram of the cloud-based system 100 illustratingan application 350 on user devices 300 with users 102 configured tooperate through the cloud-based system 100. Different types of userdevices 300 are proliferating, including Bring Your Own Device (BYOD) aswell as IT-managed devices. The conventional approach for a user device300 to operate with the cloud-based system 100 as well as for accessingenterprise resources includes complex policies, VPNs, poor userexperience, etc. The application 350 can automatically forward usertraffic with the cloud-based system 100 as well as ensuring thatsecurity and access policies are enforced, regardless of device,location, operating system, or application. The application 350automatically determines if a user 102 is looking to access the openInternet 104, a SaaS app, or an internal app running in public, private,or the datacenter and routes mobile traffic through the cloud-basedsystem 100. The application 350 can support various cloud services,including ZIA, ZPA, ZDX, etc., allowing the best in class security withzero trust access to internal apps.

The application 350 is configured to auto-route traffic for seamlessuser experience. This can be protocol as well as application-specific,and the application 350 can route traffic with a nearest or best fitenforcement node 150. Further, the application 350 can detect trustednetworks, allowed applications, etc. and support secure network access.The application 350 can also support the enrollment of the user device300 prior to accessing applications. The application 350 can uniquelydetect the users 102 based on fingerprinting the user device 300, usingcriteria like device model, platform, operating system, etc. Theapplication 350 can support Mobile Device Management (MDM) functions,allowing IT personnel to deploy and manage the user devices 300seamlessly. This can also include the automatic installation of clientand SSL certificates during enrollment. Finally, the application 350provides visibility into device and app usage of the user 102 of theuser device 300.

The application 350 supports a secure, lightweight tunnel between theuser device 300 and the cloud-based system 100. For example, thelightweight tunnel can be HTTP-based. With the application 350, there isno requirement for PAC files, an IPSec VPN, authentication cookies, orend user 102 setup.

Zero Trust Network Access Using the Cloud-Based System

FIG. 6 is a network diagram of a Zero Trust Network Access (ZTNA)application utilizing the cloud-based system 100. For ZTNA, thecloud-based system 100 can dynamically create a connection through asecure tunnel between an endpoint (e.g., users 102A, 102B) that areremote and an on-premises connector 400 that is either located in cloudfile shares and applications 402 and/or in an enterprise network 404,connected to enterprise file shares and applications. The connectionbetween the cloud-based system 100 and on-premises connector 400 isdynamic, on-demand, and orchestrated by the cloud-based system 100. Akey feature is its security at the edge—there is no need to punch anyholes in the existing on-premises firewall. The connector 400 inside theenterprise (on-premises) “dials out” and connects to the cloud-basedsystem 100 as if too were an endpoint. This on-demand dial-outcapability and tunneling authenticated traffic back to the enterprise isa key differentiator for ZTNA. Also, this functionality can beimplemented in part by the application 350 on the user device 300.

The paradigm of virtual private access systems and methods is to giveusers network access to get to an application and/or file share, not tothe entire network. If a user is not authorized to get the application,the user should not be able even to see that it exists, much less accessit. The virtual private access systems and methods provide an approachto deliver secure access by decoupling applications 402, 404 from thenetwork, instead of providing access with a connector 400, in front ofthe applications 402, 404, an application on the user device 300, acentral authority 152 to push policy 410, and the cloud-based system 100to stitch the applications 402, 404 and the software connectors 400together, on a per-user, per-application basis.

With the virtual private access, users can only see the specificapplications 402, 404 allowed by the policy 410. Everything else is“invisible” or “dark” to them. Because the virtual private accessseparates the application from the network, the physical location of theapplication 402, 404 becomes irrelevant—if applications 402, 404 arelocated in more than one place, the user is automatically directed tothe instance that will give them the best performance. The virtualprivate access also dramatically reduces configuration complexity, suchas policies/firewalls in the data centers. Enterprises can, for example,move applications to Amazon Web Services or Microsoft Azure, and takeadvantage of the elasticity of the cloud, making private, internalapplications behave just like the marketing leading enterpriseapplications. Advantageously, there is no hardware to buy or deploybecause the virtual private access is a service offering to end-usersand enterprises. FIG. 5 can include the ZPA service from Zscaler, Inc.

Digital Experience Monitoring

FIG. 7 is a network diagram of the cloud-based system 100 in anapplication of digital experience monitoring. Here, the cloud-basedsystem 100 providing security as a service as well as ZTNA, can also beused to provide real-time, continuous digital experience monitoring, asopposed to conventional approaches (synthetic probes). A key aspect ofthe architecture of the cloud-based system 100 is the inline monitoring.This means data is accessible in real-time for individual users fromend-to-end. As described herein, digital experience monitoring caninclude monitoring, analyzing, and improving the digital userexperience.

The cloud-based system 100 connects users 102 at the locations 112, 118to the applications 402, 404, the Internet 104, the cloud services 106,etc. The inline, end-to-end visibility of all users enables digitalexperience monitoring. The cloud-based system 100 can monitor, diagnose,generate alerts, and perform remedial actions with respect to networkendpoints, network components, network links, etc. The network endpointscan include servers, virtual machines, containers, storage systems, oranything with an IP address, including the Internet of Things (IoT),cloud, and wireless endpoints. With these components, these networkendpoints can be monitored directly in combination with a networkperspective. Thus, the cloud-based system 100 provides a uniquearchitecture that can enable digital experience monitoring, networkapplication monitoring, infrastructure component interactions, etc. Ofnote, these various monitoring aspects require no additionalcomponents—the cloud-based system 100 leverages the existinginfrastructure to provide this service.

Again, digital experience monitoring includes the capture of data abouthow end-to-end application availability, latency, and quality appear tothe end user from a network perspective. This is limited to the networktraffic visibility and not within components, such as what applicationperformance monitoring can accomplish. Networked application monitoringprovides the speed and overall quality of networked application deliveryto the user in support of key business activities. Infrastructurecomponent interactions include a focus on infrastructure components asthey interact via the network, as well as the network delivery ofservices or applications. This includes the ability to provide networkpath analytics.

The cloud-based system 100 can enable real-time performance andbehaviors for troubleshooting in the current state of the environment,historical performance and behaviors to understand what occurred or whatis trending over time, predictive behaviors by leveraging analyticstechnologies to distill and create actionable items from the largedataset collected across the various data sources, and the like. Thecloud-based system 100 includes the ability to directly ingest any ofthe following data sources network device-generated health data, networkdevice-generated traffic data, including flow-based data sourcesinclusive of NetFlow and IPFIX, raw network packet analysis to identifyapplication types and performance characteristics, HTTP request metrics,etc. The cloud-based system 100 can operate at 10 gigabits (10 G)Ethernet and higher at full line rate and support a rate of 100,000 ormore flows per second or higher.

The applications 402, 404 can include enterprise applications, Office365, Salesforce, Skype, Google apps, internal applications, etc. Theseare critical business applications where user experience is important.The objective here is to collect various data points so that userexperience can be quantified for a particular user, at a particulartime, for purposes of analyzing the experience as well as improving theexperience. In an embodiment, the monitored data can be from differentcategories, including application-related, network-related,device-related (also can be referred to as endpoint-related),protocol-related, etc. Data can be collected at the application 350 orthe cloud edge to quantify user experience for specific applications,i.e., the application-related and device-related data. The cloud-basedsystem 100 can further collect the network-related and theprotocol-related data (e.g., Domain Name System (DNS) response time).

Application-Related Data

Page Load Time Redirect count (#) Page Response Time Throughput (bps)Document Object Model (DOM) Load Time Total size (bytes) TotalDownloaded bytes Page error count (#) App availability (%) Page elementcount by category (#)

Network-Related Data

HTTP Request metrics Bandwidth Server response time Jitter Ping packetloss (%) Trace Route Ping round trip DNS lookup trace Packet loss (%)GRE/IPSec tunnel monitoring Latency MTU and bandwidth measurements

Device-Related Data (Endpoint-Related Data)

System details Network (config) Central Processing Unit (CPU) DiskMemory (RAM) Processes Network (interfaces) Applications

Metrics could be combined. For example, device health can be based on acombination of CPU, memory, etc. Network health could be a combinationof Wi-Fi/LAN connection health, latency, etc. Application health couldbe a combination of response time, page loads, etc. The cloud-basedsystem 100 can generate service health as a combination of CPU, memory,and the load time of the service while processing a user's request. Thenetwork health could be based on the number of network path(s), latency,packet loss, etc.

The lightweight connector 400 can also generate similar metrics for theapplications 402, 404. In an embodiment, the metrics can be collectedwhile a user is accessing specific applications that user experience isdesired for monitoring. In another embodiment, the metrics can beenriched by triggering synthetic measurements in the context of aninline transaction by the application 350 or cloud edge. The metrics canbe tagged with metadata (user, time, app, etc.) and sent to a loggingand analytics service for aggregation, analysis, and reporting. Further,network administrators can get UEX reports from the cloud-based system100. Due to the inline nature and the fact the cloud-based system 100 isan overlay (in-between users and services/applications), the cloud-basedsystem 100 enables the ability to capture user experience metric datacontinuously and to log such data historically. As such, a networkadministrator can have a long-term detailed view of the network andassociated user experience.

Unified Agent Application

FIG. 8 is a network diagram of the use of the application 350 as aunified agent application and associated connectivity and functionalitywith the cloud-based system 100. Again, the unified agent application350 is executed on a user device 300. The unified agent application 350dynamically learns all available services, adapts to changing networkenvironments, and provides a seamless and secure network resource accessto Internet and darknet hosted applications. This is achieved throughdynamic evaluation of network conditions, enrollment to individualservices, learning individual service protocols, creating a link-localnetwork on the user device 300, and establishing multiple secure tunnelsto cloud services over this local network.

The unified agent application 350 is communicatively coupled to an agentmanager cloud 606, as well as the cloud-based system 100. The unifiedagent application 350 enables communication to enterprise privateresources on the enterprise network 404 via the cloud-based system 100and to the Internet 104 via the cloud-based system 100. The agentmanager cloud 606 can communicate with enterprise asset management 614,an enterprise Security Assertion Markup Language (SAML) IdentityProvider (IDP) 616, and an enterprise Certificate Authority (CA) 618.The user device 300 and the unified agent application 350 can perform aregistration/identity 620 process through the agent manager cloud 606where the user identity, the user's certificates, and a devicefingerprint can uniquely identify the user device 300. Once registered,the unified agent application 350 has an identity 622, which can includethe user, certificates, device posture, etc. and which is shared withthe cloud-based system 100.

The unified agent application 350 operates on a client-server modelwhere an IT admin enables appropriate services for end users at a CloudAdministration Server (CAS), which can be part of the agent managercloud 606, namely the enterprise asset management 614. Every client canmake a unicast request to the agent manager cloud 606 (e.g., CAS) todiscover all enabled services. On acknowledging the response, the clientissues a request to authenticate to each service's cloud IdentityProviders, the enterprise SAML IDP 616. Authentication can bemulti-factor depending upon the nature of the service. On successfulauthentication, the server contacts Mobile Device Management (MDM) orInventory management provider to define access control rights for theuser device 300. Post authorization, the user device 300 is successfullyenrolled in the agent manager cloud 606, which tracks and monitors allbehavior of the user device 300.

Post-enrollment, the user device 300 creates a link local network with aspecific IP configuration, opens a virtual network interface to read andwrite packets to create secure tunnels to available services through thecloud-based system 100. On network changes, the user device 300dynamically evaluates reachability to pre-configured domains anddepending upon the result, it appropriately transitions all networktunnels, thus providing a seamless experience to the end user. Further,the user device 300 also intelligently learns the conditions which areappropriate for setting up network tunnels to cloud services dependingupon several network heuristics such as reachability to a particularcloud service.

Unified Agent Application−Functionality

Generally, the unified agent application 350 supports two broadfunctional categories—1) dynamic service discovery and access controlsand 2) service availability. The dynamic service discovery and accesscontrols include service configuration by the administrator, servicediscovery by the user device 300, service acknowledgment andauthentication, service authorization and enrollment, and the like. Forservice configuration by the administrator, the IT admin can providecloud service details at a centralized knowledge server, such as part ofthe agent manager cloud 606, the enterprise asset management 614, etc.The cloud service details include the service type (e.g.,Internet/intranet), network protocol, identity provider, server address,port, and access controls, etc.

For service discovery by the user device 300, the user device 300 canissue a network request to a known Cloud Administrative Server (CAS) inthe agent manager cloud 606 to discover all enabled services for a user.If a specific cloud server is not known a priori, the user device 300can broadcast the request to multiple clouds, e.g., through the agentmanager cloud 606 communicating to the enterprise asset management 614,the enterprise SAML IDP 616, and the enterprise CA 618.

For the service acknowledgment and authentication, the user device 300acknowledges the response of service discovery and initiates theauthentication flow. The user device 300 learns the authenticationprotocol through the service discovery configuration and performsauthentication of a configured nature at the enterprise SAML IDP 616.For the service authorization and enrollment, post successfulauthentication, the CAS authorizes the user device 300, and fetches theaccess control information by contacting an MDM/Inventory SolutionsProvider. Depending upon the user context and the nature of access, theCAS enrolls the user device 300 into several cloud services and informsthe cloud services that the user has been enrolled for access.

The service availability includes link local network setup, a trafficinterceptor, and dynamic traffic forwarding tunnels to authorizedservices. The link-local network setup, post-enrollment, has the userdevice 300 create a local network on the user device 300 itself tomanage various networking functionalities. For the traffic interceptor,the user device 300 intercepts and evaluates all Internet traffic.Allowed traffic is tunneled to the cloud services such as in thecloud-based system 100, whereas the rest of the traffic is denied as perenterprise policies. For the dynamic traffic forwarding tunnels toauthorized services, depending upon the evaluation, the user device 300splits the traffic into the different tunnel to individual cloudservices such as in the cloud-based system 100.

The unified agent application 350 is a single application that providessecure connectivity to the Internet 104 and darknet hosted applications,such as the enterprise private resources in the enterprise network 404.The unified agent application 350 communicates securely to the agentmanager cloud 606, which is controlled by an IT admin. The unified agentapplication 350 learns available services and authenticates with eachservice. Post proper enrollment, the unified agent application 350securely connects to cloud services by means of network tunnels.

Unified Agent Application—Workflow

FIG. 9 is a network diagram of the example workflow of the unified agentapplication 350. The user device 300 again executes the unified agentapplication 350, as well as a browser 630 (or some other applicationrequesting network services). First, the user device 300 includesauthentication through an application portal 632 and download/install ofthe unified agent application 350 therefrom (step 640-1). Note, theapplication portal 632 can be a website, Apple's app store, Google Play,Windows Store, etc. Once installed, the unified agent application 350communicates to the agent manager cloud 606, communicating identity andasking for available services (“I am User X, what are my services?”) andthe agent manager cloud 606 responds with the available services (“Youhave Z services”) (step 640-2).

Next, the unified agent application 350 includes authentication using aVPN Service Provider (SP) with the security cloud 608 (step 640-3). Theunified agent application 350 next enrolls the user device 300 throughthe agent manager cloud 606 (step 640-4). The agent manager cloud 606performs a device asset policy check with the enterprise assetmanagement 614 (step 640-5). The agent manager cloud 606, upon thesuccessful check, provides the unified agent application 350 anaffirmative response (step 640-6). The unified agent application 350sends a Certificate Signing Request (CSR) to the agent manager cloud 606(step 640-7), and the agent manager cloud 606 sends the CSR request tothe enterprise CA, and the certificate is returned to the unified agentapplication 350 (step 640-8). Finally, the unified agent application 350enables VPN connectivity to the security cloud 608 (step 640-9).

FIG. 10 is a flow diagram of an event sequence associated with theunified agent application 350. The event sequence is shown between theuser device 300 executing the unified agent application 350, a mobileadmin function 650 such as implemented through the agent manager cloud606, an enforcement node 150, a VPN node 652 such as through thesecurity cloud 608, an MDM function 654 such as through the enterpriseasset management 614, and an IDP function 656 such as through theenterprise SAML IDP 616. The user device 300 discovers services with themobile admin function 650 (step 660), and the user device 300 isauthenticated by the IDP function 656 (step 662). The user device 300enrolls in discovered services through the mobile admin function 650(step 664).

The mobile admin function 650 is configured to authorize the serviceswith the MDM function 654 (step 666), enroll in the services through theVPN node 652 (step 668), and the enforcement nodes 150 (step 670). Asuccess/error is provided by the mobile admin function 650 to the userdevice 300 (step 672). Subsequently, the user device 300, through theunified agent application 350, accesses the services such as a securetunnel for internet access through the enforcement nodes 150 (step 674)or a secure tunnel for intranet access through the VPN node 652 (step676).

Unified Agent Application—Architecture

FIG. 11 is a logical diagram of the functional components of the unifiedagent application 350. The unified agent application 350 is configuredto operate on the mobile user device 300. The cloud-based system 100 canprovide Internet security as well as cloud-based remote access toenterprise internal resources through a VPN. These cloud services aredesigned and well suited for road warriors. Road warriors are the userswho are accessing the Internet 104 and enterprise internal services fromoutside the corporate physical network perimeter. These are the users102 who are accessing the Internet 104 and Enterprise resources fromhome, airports, coffee shops, and other external unsecured hotspots.

The unified agent application 350 provides authenticated and encryptedtunnels from road warrior devices 300 and, in some use cases, it evenneeds to be enforceable so that end users cannot disable the unifiedagent application 350. The VPN, which is the remote access service, alsoneeds authenticated and encrypted tunnel from road warrior user devices300. Both of these solutions also need to provide feedback to the enduser in the event that access was blocked due to security or compliancereasons. The following describes the architecture and design of theunified agent application 350, including an endpoint clientarchitecture, backend changes, auto-update, and integration with thecloud-based system 100.

The unified agent application 350 includes logical components includingview components 702, business processes and services 704, data 706, andcross-cutting functions 708. The view components 702 include UserInterface (UI) components 710 and UI process components 712. Thebusiness processes and services 704 include a tray user process 714, ahelper user process 716, a tunnel system service 718, a posture systemservice 720, and an updater system service 722. The data 706 includesencrypted data 724, configuration data 726, and logs 728. Thecross-cutting functions 708 are across the view components 702, thebusiness processes and services 704, and the data 706 and includesecurity 730, logging 732, and statistics 734.

The unified agent application 350 has a useful goal of simplifiedprovisioning of the proxy (for security through the cloud-based system100 to the Internet 104) and the VPN (for access through the cloud-basedsystem 100 to the enterprise private resources in the enterprise network404). That is, the unified agent application 350 allows the use of thecloud-based system 100 as a proxy for Internet-bound communications. Theunified agent application 350 further allows the use of the cloud-basedsystem 100 as a tunnel for Intranet-bound communications to theenterprise private resources. With the unified agent application 350setting up a local network at the user device 300, the unified agentapplication 350 can manage communications between the Internet and theintranet, i.e., two of the main categories of cloud services—proxy tothe Internet and tunnel to the intranet. The unified agent application350 further has objectives of simplified user enrollment in the proxyand tunnels.

In an embodiment, the unified agent application 350 is a nativeapplication. The common functionality is abstracted out and made intocommon libraries based on C or C++ so that it can be reused acrossdifferent platforms (e.g., iOS, Android, etc.). Example functionality:Traffic forwarding tunnels, local proxy, authentication backend,logging, statistics, etc. The UI components 710 and UI processcomponents 712 can be platform dependent. Also, the unified agentapplication 350 is designed and implementable such that otherthird-party VPN applications, if configured by the enterprise, can beused concurrently.

The app portal 632 enables the installation of the unified agentapplication 350 on the user device 300. For example, an admin may beable to push and install the unified agent application 350 to the userdevice 300 using remote-push mechanisms like GPO, MDMs, etc.Additionally, the user can download the unified agent application 350 ifthey have access to the installation file and install it on their own.The unified agent application 350 supports automatic updates withoutimpacting the user's Internet experience. If a problem is encountered,then it should roll back to the previously successful state or failopen. The unified agent application 350 can have a security check toensure that it is not tampered and updated from the right source with ahash match with a source hash when upgrading.

The user can log into the unified agent application 350. Once the usersends their User ID through the unified agent application 350 to theagent manager cloud 606, the security cloud 608, and/or the app portal632, the app portal 632 can determine the company's authenticationmechanism, such as through a lookup in the enterprise asset management614, and validate password through the enterprise CA 618.

Through the unified agent application 350, a user can be authenticatedto the proxy or the VPN through the security cloud 608. Forauthentication of the user to the proxy, using SAML, the user can loginto the unified agent application 350 by using their user ID andtransparent SAML authentication thereafter, including SAML certificate.The app portal 632 shall determine that an organization is using SAMLfor authentication through the enterprise CA 618 and redirect to theenterprise SAML IDP 616 to get SAML assertion and use it to authenticatethe user.

For authentication of the user to the tunnel, using SAML, the user canlog into the unified agent application 350 by just using their user IDand based on the user ID, the unified agent application 350 shallredirect the user for authentication to enterprise SAML IDP 616 and SAMLassertion shall be sent. The VPN service shall validate SAML assertion;if the assertion is valid, then the unified agent application 350 shallcollect hardware parameters like device serial number, model number,etc. and create CSR. The CSR shall be signed by the enterprise CA 618,and the certificate shall be pushed to the unified agent application350. The unified agent application 350 shall install the certificate toKMS/keychain and save assertion.

After the user has been successfully authenticated, the user shall beenrolled in the proxy service, and the user's traffic forwarding profileshall be downloaded from unified agent application 350, including SecureSockets Layer (SSL) certificates and exceptions. The unified agentapplication 350 shall indicate that the user is connected to cloud-basedsystem 100, and app statistics shall be populated.

After the user has successfully authenticated (including transparentauthentication), the user shall be enrolled with a VPN service, and theVPN broker info shall be downloaded by the unified agent application350, and the VPN tunnel shall be established. The unified agentapplication 350 can support captive portal detection to fail open whenusers are behind a captive portal to allow connection to a captiveportal.

The unified agent application 350 can forward internal enterprisetraffic from the user device 300 to the VPN. The unified agentapplication 350 can recognize when a user goes to an internal app thatis provisioned with the VPN service. The unified agent application 350shall auto-enable a tunnel to the VPN service when the user triesconnecting to an internal app. The proxy service can always be enforced,and the user is not able to remove it by switching off the tunnel orremoving the unified agent application 350. Without the proxy solutionenforced, the user is not able to access the Internet and would beprompted to restart the web security service, via the unified agentapplication 350.

The VPN is an on-demand service, unlike the proxy service that shall beenforceable by default so that the user can enable/disable the VPN atwill without any password requirements. Once the user logs into the VPNservice using a ‘Connect,’ the same button shall be labeled‘Disconnect,’ and the user shall be able to disconnect the VPN servicewith a single click. Every time user disconnects with VPN service. TheVPN service can be auto-disabled if the user puts their system to sleepmode or there is inactivity (no packets exchanged) after x minutes (xshall be configurable in the VPN settings).

The admin can turn off the proxy service with a single client from anadmin UI for a user, all users, or some subset of users. This does notremove the unified agent application 350 from the user device 300. Auser may be able to disable the proxy service, provided they have theauthority and credentials. The unified agent application 350 can provideservice-related notifications to the user. For example, the unifiedagent application 350 can provide notifications such as push alerts orthe like as well as contain a notification area for a single place toshow all notifications that are generated by the proxy service and theVPN service. This shall also include app notifications, includingconfiguration updates, agent updates, etc. The user shall be able toclear notifications as well as filter notifications from this screen.This shall include a filter for VPN/Proxy, blocked, cautioned,quarantine actions.

Unified Agent Application—User Workflow

Again, the unified agent application 350 is executed on the user device300. For authentication, the user enters a User ID in the unified agentapplication 350, such as userid@domain. Subsequently, the unified agentapplication 350 is configured to discover the services enabled—proxyservice and VPN services based on userid@domain. The user authenticateswith the presented services, i.e., proxy service, VPN services, andcombinations thereof. The unified agent application 350 isauto-provisioned for the authenticated service by downloading theservice-specific configuration. The unified agent application 350performs the following during VPN enrollment—get the User/Devicecertificate signed by an Enterprise Intermediate Certificate. ThisIntermediate Certificate will be the same, which will be used forsigning Assistants. The unified agent application 350 also will pinhardware signatures/fingerprints to the certificate and user, e.g.,Storage Serial ID (Hard Drive Serial ID), CPU ID, Mother Board SerialID, BIOS serial number, etc.

Unified Agent Application—Authentication and Enrollment Protocol

FIG. 12 is a flowchart of a proxy authentication process 750 to thecloud-based system 100. For authentication in the proxy service,conventionally, devices 300 can use proxy authentication to register tothe cloud-based system 100. This is not truly reliable as it depends onlocation/location-authentication policy/VPN and other such factors towork correctly. To simplify this flow, the following new flow can beused with the unified agent application 350 for the process 750. First,the mobile client user device 300 initiates an HTTPS request to a CA(e.g., the enterprise CA 618) (step 752). For example, this can be asfollows:

-   login.zscaler.net/clstart?version=1&_domain=nestle.com&redrurl=<url-encoded-url-with-schema>    If the domain is invalid or if the redrurl is missing, CA will reset    the connection.

The above endpoint begins the client auth flow (step 754). The provideddomain is the company that requires the auth. The CA looks up the domainto find the company and their auth mechanism. If the company uses hostedor Active Directory (AD)/Lightweight Directory Access Protocol (LDAP)authentication [SAML auth flow starts at step 760], the response will bea login form with input fields for [username] & [password] (step 756).The form is submitted via POST to the CA at a below endpoint:

-   https://login.zscaler.net/clicred. The HTTP content may look like    below-   POST /clicred-   Host: login.zscaler.net-   Content-Length: xyz    username=xyz@nestle.com&password=123456&redrurl=<url-encoded-posturl-with-schema>

Next, the CA performs user/password validation and responds with themessage explained in step 762 (step 758). If the company uses SAML, theresponse to the request in step 752 will be the SAMLRequest form. TheSAMLRequest form will auto-submit to the IDP. Once auth completes, theCA gets control back with the identity of the user. Once SAMLResponsecomes back, send the response as a 307 redirect to redrurl with a belowformat

-   Location: zsa://auth[?token=encrypted-cookie& . . . ] to be    appended.-   307 query params-   token=(on success)-   ecode=(on error)-   emsg=(on error)-   On error, send the same redrurl with below format-   zsa://auth?ecode=<code>&emsg=<message>

FIG. 13 is a flowchart of a VPN authentication process 780 to thecloud-based system 100. The client (user device 300) issues a GET webrequest to the VPN authentication server with the domain name as thequery parameter (step 782), such as:

-   GET //<auth-server>?domain=mockcompany.com    The server identifies the IDP for the given domain and responds with    a Hypertext Markup Language (HTML) page containing a SAML Request    (step 784). The client will redirect to the IDP with the SAML    Request (step 786). The IDP will challenge the client for    credentials, which can be of the form of a username/password or    client identity certificate (step 788). On successful    authentication, IDP will generate a SAMLResponse for the VPN    authentication server (step 790). The client will record the    SAMLAssertion for future tunnel negotiation. In the case of error,    the server will resend the challenge to the user (step 792).

FIG. 14 is a flowchart of a device enrollment process 800 for the clientuser device 300 and the unified agent application 350. Post successfulauthentication with all services, in this case, the proxy services andthe VPN services, the client sends an enrollment request to mobile admin(Cloud Administrative Server CAS) (step 802). The request contains adevice fingerprint and an authentication context for each service toidentify the user (step 804). For example, the security cloud 608 canuse cookies, and the VPN can use SAMLAssertion for the authenticationcontext. The mobile admin (agent manager cloud 606) performs inventorylookup with device fingerprints at the MDM server to authorize the userand the user device 300 (step 806). On successful authorization, themobile admin server enrolls the user to cloud services with theirauthentication contexts (step 808). Each cloud service responds withspecific access controls and protocol information that the clientreceives from mobile admin and uses for local network setup (step 810).

Unified Agent Application—Traffic Interception and Splitting

Again, to protect Internet-bound traffic and simultaneously accessenterprise-specific Intranet traffic, the user device 300 needs toconnect through multiple applications. Again, it is not straightforwardfor users to configure these applications in different networks, anddifferent VPN and proxy solutions arise compatibility issues whenoperating simultaneously. The unified agent application 350 is designedto solve all these issues. The unified agent application 350 handlesboth proxy (Internet-bound) traffic and Enterprise Intranet boundtraffic. The unified agent application 350 provides secure access toOrganizational internal resources when the user is outside of theenterprise network. For Internet-bound traffic, it will forward trafficto the enforcement node 150, and for intranet bound traffic, it willforward traffic to a VPN (Broker) or direct if the user is inside theorganization network.

The unified agent application 350 is configured to intercept alltraffic, specifically to intercept all Transmission Control Protocol(TCP) traffic and DNS traffic before it goes out through the externalnetwork interface in the user device 300. The unified agent application350 can intercept other types of traffic as well, such as the UserDatagram Protocol (UDP). The unified agent application 350 is configuredto split traffic at the user device 300, i.e., based on a local networkconfigured at the user device 300. Split traffic based upon port,protocol, and destination IP. The unified agent application 350 isconfigured to send VPN traffic direct for trusted networks(organization's internal network). The unified agent application 350 canalso coexist with other VPN clients, i.e., it does not intercept thetraffic targeted for those interfaces by specific routes.

Thus, the unified agent application 350 is configured to intercept alltraffic at the IP layer for the device 300 or other VPN client's defaultroute. Then, the unified agent application 350 is configured to splittraffic. Based upon port, protocol, and destination IP as configured bythe IT administrator

FIG. 15 is a flowchart of a traffic interception process 820 implementedthrough the unified agent application 350. The unified agent application350 registers and sets up a new Network Adapter (TUN interface) on thedevice (step 822). The unified agent application 350 overrides thedevice's network default route by configuring the default route ofhigher priority for the TUN interface (step 824). The unified agentapplication 350 sets a specific route (exact match) for all DNS serversconfigured on the user device 300 with the highest priority (step 826).The unified agent application 350 will not override other specificroutes of an external adapter or other VPN clients (step 828).

For each IP packet coming to the TUN interface, packet processing isperformed (step 830). The application does a <port, protocol,destination-IP> lookup on every IP packet and sends it on one of thededicated tunnels based upon configured rules of packet transport.

FIG. 16 is a flow diagram of traffic interception and splitting 850using the unified agent application 350. Again, the unified agentapplication 350 creates and operates a tunnel (TUN) interface 852 on theuser device 300. The user device 300 includes one or more clientapplications 854, which can be any program or service executable on theuser device 300, which requires access to the network interface on theuser device 300. Traffic for the default route from the clientapplications 854 is sent to the TUN interface 852, but traffic forspecific routes can be sent to other interfaces 856, separate from theTUN interface, for direct connectivity to the Internet 504, such as viaVPN services or direct.

The TUN interface 852 splits 858 all traffic. TCP traffic for internaldomains is sent to a VPN/broker server 860, TCP port 80/443 traffic issent to the security cloud 608 for a proxy such as to the enforcementnode 150. Finally, other traffic can be sent directly to the Internet504. In this manner, the TUN interface 852 operates a local network atthe user device 300.

FIG. 17 is a flow diagram of tunnel forwarding rules 940 by the unifiedagent application 350. A periodic health monitor function 942 operates,based on a periodic timer 944, to check a PAC ping and a gateway connectping to provide a state to a bypass fail/open module 946. A networkstate change function 948 is configured to detect a network change event950 such as DNS server address, DNS search domains, on-net host DNSlookups, etc., and to provide a state to the bypass fail/open module946. The bypass fail/open module 946 creates an active tunnel 952 ordisabled tunnel 954 based on the states.

Service Driven Split Tunneling

FIG. 18 is a flowchart of a service drive split tunneling process 1000.The service drive split tunneling process 1000 provides betterscalability, security, and segmentation of traffic in mobile and cloudenvironments. The service-driven split tunneling process 1000 caninclude the traffic interception and splitting 850 using the unifiedagent application 350. Again, as illustrated in FIG. 18, the unifiedagent application 350 creates and operates a tunnel (TUN) interface 852on the mobile user device 300. The mobile user device 300 includes oneor more client applications 854, which can be any program or serviceexecutable on the user device 300, which requires access to the networkinterface on the user device 300. Traffic for the default route from theclient applications 854 is sent to the TUN interface 852, but trafficfor specific routes can be sent to other interfaces 856, separate fromthe TUN interface, for direct connectivity to the Internet 504, such asvia VPN services or direct.

The service drive split tunneling process 1000 includes a mobileapplication/agent which is installed on a mobile device for packetinterception (step 1002). For example, the mobile application/agent canbe the unified agent application 350 on the mobile user device 300. Themobile application/agent can inject a default route on the mobile devicepointing to its own interface to get all Layer 2 or Layer 3 packets.

The mobile application/agent is configured with a set of rules (step1004). The set of rules can be learned at runtime (as the mobileapplication/agent operates, configured at application launch, configuredduring application operation, and a combination thereof. For example,the set of rules can be configured by IT administrators for specificusers, groups, departments, etc. and sent to the mobileapplication/agent. Further, the set of rules can be learned based on theoperation of the mobile application/agent.

The set of rules can be an array of tuples of included and excludedtraffic. For example, the array of tuples can include the followingformat

-   -   <exclude, destination_port, protocol, destination_IP        address_subnet>    -   <include, destination_port, protocol, destination_IP        address_subnet, transport type>

For example, a set of rules can include

-   -   <include, 443, TCP, 17.0.0.0/8, <TCP, gateway.zscaler.net:80        This rule would tunnel all TCP port 443 traffic destined to        17.0.0.0/8 subnet over a TCP transport on port 80 to host.com.        Another rule can include    -   <exclude, 53, UDP, *>        This rule does not tunnel any UDP port 53 (DNS) traffic, but        rather sends it direct.

Based on the set of rules, the mobile application/agent opens tunnels todifferent host concentrators (step 1006). As described herein, the hostconcentrators can be the enforcement nodes 150, etc. The tunnel may ormay not be authenticated depending upon the requirements. For thetraffic that needs to go direct, the mobile application/agent proxiesthe connections locally through a RAW Socket or via a custom TCP/IPStack embedded within the application itself.

The mobile application/agent intercepts packets on the user device andforwards over the tunnels based on the set of rules (step 1008). Throughthis granular splitting of network traffic, IT administrators will havebetter control of the network traffic in terms of security andscalability. For instance, an IT admin can now control that only specialtraffic such as Session Initiation Protocol (SIP) should go outside thetunnel, and rest should go to some security gateway or vice versa. Anynumber of complex rules is hence possible.

End users will also have significant performance benefits overtraditional SSL/IPSec VPNs where traffic of different needs compete witheach other. The service drive split tunneling process 1000 allowsfunction-driven security and on-demand scalability for differentservices. So, File Transfer Protocol (FTP) traffic goes to a secure FTPproxy, Web traffic (TCP, port 80 traffic) goes to a Web proxy, HTTPS(TCP, port 443) goes to an SSL acceleration proxy, SIP traffic goes toSIP traffic processing concentrator and so on.

Hybrid Architecture for Security Processing

Again, the present disclosure relates to mobile devices, which are onesubset of the user device 300, referred to herein as a mobile device300. The present disclosure relates to systems and methods for enforcingsecurity policies on mobile devices 300 in a hybrid architecture. Here,the hybrid architecture means security processing occurs both via theapplication 350 and the cloud-based system 100 in a unified andcoordinated manner. The hybrid architecture utilizes the application 350first to generate a local decision about whether to BLOCK/ALLOWconnections based on a local map. If a connection is not in the localmap, the application 350 forwards a request to the cloud-based system100 to generate a decision. In this manner, the hybrid architecturedecreased bandwidth consumption between the mobile device 300 and thecloud-based system 100 by utilizing the previous BLOCK information. Thehybrid architecture decreases processor utilization on the mobile device300 by relying on a cloud service through the cloud-based system 100 forcalculating request signatures, detecting malware, detecting privacyinformation leakage, etc. That is, the application 350 makes simpledecisions—ALLOW or BLOCK, and the cloud-based system 100 does advancedprocessing where needed, sandbox, advanced threat detection,signature-based detection, DLP dictionary analysis, etc.

This approach also decreases the average latency, specifically forblocked requests. A user 102 gets an immediate block as opposed to adelay based on an exchange with the cloud service. Finally, this hybridarchitecture approach increases the coverage of securitypolicies/signature-based checks on mobile devices 300, because the cloudbased system 100 has significant processing capability relative to themobile device 300. Here, the application 350 is coordinating with thecloud service. The actual policies are configured in a cloud portal ofthe cloud-based system 100 and immediately promulgated to correspondingmobile devices 300. The application 350 serves as a gatekeeper toprocess simple requests, namely BLOCK/ALLOW connections, based onentries in a local map. The cloud-based system 100 processes complexrequests, where entries are not in the local map or where other securitypolicies require, such as where data requires DLP analysis, etc. Again,mobile devices 300 have limited battery, storage, processingcapabilities. The application 350 is lightweight and operatesconsidering these limitations.

FIG. 19 is a flowchart of a process 1100 for security processing in ahybrid architecture. The process 1100 is described with reference tosteps implemented at a mobile device 300, and those skilled in the artwill recognize functions are also performed in the cloud-based system100. The process 1100 contemplates implementation as a method, via themobile device 300, and as computer-executable instructions stored in anon-transitory computer-readable medium storing.

The process 1100 includes intercepting traffic on the mobile device 300based on a set of rules (step 1102); determining whether a connectionassociated with the traffic is allowed based on a local map associatedwith an application 350 (step 1104); responsive to the connection beingallowed or blocked based on the local map, one of forwarding the trafficassociated with the connection when allowed and generating a block ofthe connection at the mobile device 300 when blocked (step 1106); and,responsive to the connection not having an entry in the local map,forwarding a request for the connection to a cloud-based system 100 forprocessing therein (step 1108). The cloud-based system 100 is configuredto allow or block the connection based on the connection not having anentry in the local map.

There can be multiple different local maps, such as a firewall map, adomain map, and an HTTP request map. The firewall map can be the firstmap to consult for every connection. It has rules based on destinationIP address, protocol, and port. The domain map, after the firewall map,can be consulted for HTTP and HTTPS connections. For HTTP, theapplication 350 can use the domain in the HTTP host header, and forHTTPS, the application 350 can use Server Name Indication (SNI). Afterthe domain map, the HTTP domain map is consulted for HTTP requests, thismap will have different set of rule categories such as: a) HTTP requesttype: Match HTTP domain (optional) and request type like GET/POST/HEAD,etc., b) HTTP header: Match HTTP request header key:value(optional)pairs and domain (optional), c) HTTP Version: Match Http version anddomain (optional), d) Whole HTTP payload: Match HTTP request payloadSHA256 hash by excluding specific request headers.

The process 1100 can further include receiving an update from thecloud-based system 100 based on the forwarding the request to thecloud-based system 100; and updating the local map based on the update.Here, the application 350 is configured to cache previous decisions thatwere made by the cloud-based system 100. The process 1100 can furtherinclude receiving periodic updates from the cloud-based system 100; andupdating the local map based on the periodic updates. Here, the periodicupdates can be based on new security policies for a tenant of the user,detections of connections as malware or other malicious content forblocking, etc. The periodic updates can be based on monitoring in thecloud-based system and on policy of a tenant associated with a user ofthe mobile device.

The process 1100 can also include timing out entries in the local mapand removing timed out entries. Here, the local map can have entriespurged over time. This is not an issue as the fallback for anyconnection not found in the local map is processing in the cloud-basedsystem 100. Thus, the local map does not need to have every possibleconnection entered in the local map; only ones that are used regularly.Each object within the map can have their own timeout determined basedon the nature of block, e.g., for a firewall block, it can be more, and,for HTTP request payload block, it could be less.

In an embodiment, the traffic includes Hypertext Transfer Protocol(HTTP) and HTTP Secure (HTTPS) requests. The application 350 canintercept the HTTP/HTTPS requests on the mobile device 300 by means ofroute based rules. The routes added by the application 350 redirect allthe traffic to itself via a virtual tun/tap adapter. For each incomingHTTP/HTTPS request, the application 350 consults the local mapindicating if the connection needs to be blocked. In the case of BLOCK,it generates a local BLOCK response and sends it to the clientapplication that generated the traffic. If the entry for this particularconnection does not exist in the local map, the request is forwarded tothe cloud service. Every BLOCK response from the cloud service can besaved locally in the local map for future consultation. There areseveral types of maps maintained on the client based on the type ofBLOCK received from the cloud service. The process 1100 alsocontemplates non-HTTP/HTTPS traffic as well.

For a firewall map, if the request is forwarded to the cloud, a cloudfirewall can provide the BLOCK and the decision can be provided to thelocal firewall map for future traffic. The updates between theapplication 350 and the cloud-based system 100 can be based on a tunnel.For example, a tunnel used between the mobile device 300, theapplication 350, and an enforcement node 150 can include informationexchanged related to BLOCKs and the associated reasons. For example,DLP_VIOLATION, PROTOCOL_ACCESS_DENIED, etc. The local map can bepopulated based on the tunnel data.

Adaptive Multipath Traffic Forwarding

Again, the present disclosure describes adaptive multipath trafficforwarding mechanisms for better performance and resource utilization inmobile and cloud environments. The present disclosure contemplatesoperation with the user device 300 as a mobile device executing theapplication 350 and with connectivity to the cloud-based system 100.

FIG. 20 is a flowchart of a process 1200 for adaptive multipath trafficforwarding. The process 1200 is described with reference to stepsimplemented at a mobile device 300 that communicates with thecloud-based system 100. The process 1200 contemplates implementation asa method, via the mobile device 300, and as computer-executableinstructions stored in a non-transitory computer-readable mediumstoring.

The steps in the process 1200 include installing the application 350 onthe mobile device 300 and configuring the application for interceptingpackets (step 1202). As described herein, the application 350 includes apacket interception module that can either install a virtual interfaceor can apply a network filter to get all Layer 2 and Layer 3 packets.The application 350 is configured to discover all link-layer channelsavailable for traffic forwarding (step 1204). The link layer is thelowest layer in a networking architecture. The link layer is the groupof techniques and communications protocols confined to the link that ahost is physically connected to. The link is the physical and logicalnetwork component used to interconnect the mobile device 300 in thenetwork and a link protocol is a suite of processes and standards thatoperate only between adjacent network nodes of a network segment. Thelink layer is sometimes described as a combination of the data linklayer (layer 2) and the physical layer (layer 1) in the OSI model. For apractical embodiment of a mobile device 300, the link-layer channels caninclude Wi-Fi (IEEE 802.11 and variants thereof), Bluetooth, Ethernet,wireless cellular channels, etc. For example, the wireless cellularchannels can include GSM, EDGE, LTE, 5G, etc. The application 350determines every link-layer channel's characteristics (step 1206). Thisstep can include measuring the bandwidth and throughput by doing someexample data exchange with the secure gateway (e.g., the enforcementnode 150), i.e., a speed test.

The application is configured with a set of traffic forwarding rules(step 1208). Here, the set of traffic forwarding rules can be configuredby an IT administrator, and may include a default set of rules. Therules can be a list of tuples of IP addresses or domains with assignedpriorities such as HIGH, DEFAULT, LOW and the destination secure gateway(e.g., the enforcement node 150). For instance: <10.0.0.0/8, HIGH,gateway.zscaler.net>, <Youtube.com, LOW, gateway.zscaler.net >, <*,DEFAULT, gateway.zscaler.net> translates to the traffic to Intranetshould be given high priority over youtube.com traffic and all the othertraffic has default priority and can be tunneled through any availablechannel to a gateway, gateway.zscaler.net, such as an enforcement node150 in the cloud-based system 100. The IT admin may also choose totunnel different gateways depending upon the needs.

The steps 1202-1208 include configuration steps. Subsequent to theconfiguration steps, the application intercepts the traffic and appliesthe rules to find the best possible link of the link-layer channels forforwarding IP packets (step 1210). Note, each of the link-layer channelsis configured with a secure tunnel from the mobile device 300 to thecloud-based system 100, and the application 350 is configured to routepackets to the appropriate tunnel in a given link-layer channel, such asusing the virtual interface or network filter.

Responsive to a network change, the application 350 can do a seamlesshandover of all the IP packets flowing one tunnel to the other tunnelwithout breaking any end user network connections (step 1212). When newlink layers channel come up, the application 350 can establish a newtunnel to the secure gateway using the same session information as usedin other tunnels (step 1214). Typically, a mobile device 300 will remainconnected to the wireless cellular channels, but may come and go intoWi-Fi networks. Here, when Wi-Fi is connected, the application 350 canestablish new tunnels on those corresponding link-layer channels.

The application 350 can periodically update its statistics on the linklevel channel capacity to dynamically make routing decisions as thethroughput capacities and usage for a particular link increase ordecrease (step 1216). For instance, based on user's subscription plan,the Wi-Fi speed might reduce after a prolonged period of usage, beyondwhich data transfer over cellular channel will become more efficientthan Wi-Fi.

Advantages of Adaptive Multipath Traffic Forwarding

The present disclosure includes a performance-driven tunneling solutionfor mobile devices that has several advantages as follows.

First, there is increased throughput to the sum of all availablelink-level channels. Conventionally, SSL or IPSec VPNs use only a singlechannel to forward all user traffic which greatly limits the possiblethroughput. The solution uses multiple available paths for trafficforwarding to secure web gateways (such as the enforcement nodes 150),which can be on-premise or in the cloud-based system 100. Using multiplechannels to forward user traffic allows for maximum resource usage asall available paths are utilized, thus providing the best possible userexperience.

Second, this approach supports prioritized network traffic and forpreemption. The tunneling approach provides a way for IT administratorto prioritize access to work-related mission-critical applications andresources instead of, for example, media traffic that is not importantfor work. Thus, an IT administrator might choose to give priority toOffice365 applications instead of streaming media to end users forbetter utilization of network traffic. The solution also provides forpreemption allowing higher priority network traffic to be tunneledbefore the lower priority network traffic, thus allowing support forgranular control on end user traffic shaping.

Third, the tunneling solution supports fault tolerance. Using multiplepaths for traffic forwarding allows for better control for user'snetwork traffic in case of network failures on one or more availablechannels. Also, as mobile devices hop from one network to another,user's traffic is not impacted and can continue over available activechannels. Hence, links may be added or dropped as the user moves in orout of coverage without disrupting the existing and new end-to-endTCP/UDP connections. The session information is shared across allavailable tunnels thus allowing fast renegotiations with the securegateway.

Finally, the tunneling solution supports compatibility with existingnetworking devices. The proposed solution is compatible with existingmiddleboxes such as NATs, Proxies and Network malware scanning systemand does not need any upgrades to networking infrastructure which is asignificant problem in implementing multipath TCP as it creates crosspath data fragmentation causing firewalls and malware scanners to abortmTCP connections immediately.

It will be appreciated that some embodiments described herein mayinclude one or more generic or specialized processors (“one or moreprocessors”) such as microprocessors; Central Processing Units (CPUs);Digital Signal Processors (DSPs): customized processors such as NetworkProcessors (NPs) or Network Processing Units (NPUs), Graphics ProcessingUnits (GPUs), or the like; Field Programmable Gate Arrays (FPGAs); andthe like along with unique stored program instructions (including bothsoftware and firmware) for control thereof to implement, in conjunctionwith certain non-processor circuits, some, most, or all of the functionsof the methods and/or systems described herein. Alternatively, some orall functions may be implemented by a state machine that has no storedprogram instructions, or in one or more Application-Specific IntegratedCircuits (ASICs), in which each function or some combinations of certainof the functions are implemented as custom logic or circuitry. Ofcourse, a combination of the aforementioned approaches may be used. Forsome of the embodiments described herein, a corresponding device such ashardware, software, firmware, and a combination thereof can be referredto as “circuitry configured or adapted to,” “logic configured or adaptedto,” etc. perform a set of operations, steps, methods, processes,algorithms, functions, techniques, etc. as described herein for thevarious embodiments.

Moreover, some embodiments may include a non-transitorycomputer-readable storage medium having computer-readable code storedthereon for programming a computer, server, appliance, device,processor, circuit, etc. each of which may include a processor toperform functions as described and claimed herein. Examples of suchcomputer-readable storage mediums include, but are not limited to, ahard disk, an optical storage device, a magnetic storage device, a ROM(Read Only Memory), a PROM (Programmable Read-Only Memory), an EPROM(Erasable Programmable Read-Only Memory), an EEPROM (ElectricallyErasable Programmable Read-Only Memory), Flash memory, and the like.When stored in the non-transitory computer-readable medium, software caninclude instructions executable by a processor or device (e.g., any typeof programmable circuitry or logic) that, in response to such execution,cause a processor or the device to perform a set of operations, steps,methods, processes, algorithms, functions, techniques, etc. as describedherein for the various embodiments.

Although the present disclosure has been illustrated and describedherein with reference to preferred embodiments and specific examplesthereof, it will be readily apparent to those of ordinary skill in theart that other embodiments and examples may perform similar functionsand/or achieve like results. All such equivalent embodiments andexamples are within the spirit and scope of the present disclosure, arecontemplated thereby, and are intended to be covered by the followingclaims.

What is claimed is:
 1. A non-transitory computer-readable medium storingcomputer-executable instructions, and in response to execution of anapplication on a mobile device, the computer-executable instructionscause the mobile device to perform the steps of: establishing aplurality of tunnels to a gateway, wherein each of the plurality oftunnels is on one of a plurality of link layer channels at the mobiledevice; intercepting network traffic on the mobile device; forwardingthe network traffic to one of the plurality of tunnels based on a set oftraffic forwarding rules; and responsive to a network change for themobile device, managing the plurality of tunnels and continuing theforwarding based on the managing.
 2. The non-transitorycomputer-readable medium of claim 1, wherein the steps further includedetermining characteristics including bandwidth of each of the pluralityof link layer channels; and utilizing the characteristics with the setof traffic forwarding rules for the forwarding.
 3. The non-transitorycomputer-readable medium of claim 1, wherein the steps further includeconfiguring the application with the set of traffic forwarding rules. 4.The non-transitory computer-readable medium of claim 1, wherein the setof traffic forwarding rules include a tuple of address or domain,assigned priority, and address of the gateway.
 5. The non-transitorycomputer-readable medium of claim 1, wherein each of the plurality oftunnels is a lightweight tunnel that is Hypertext Transfer Protocol(HTTP)-based.
 6. The non-transitory computer-readable medium of claim 1,wherein the intercepting is via one of a virtual interface and a networkfilter.
 7. The non-transitory computer-readable medium of claim 1,wherein the plurality of link layer channels include a wireless cellularchannel and a Wi-Fi channel.
 8. The non-transitory computer-readablemedium of claim 1, wherein the managing includes adding or removingtunnels based the network change.
 9. The non-transitorycomputer-readable medium of claim 1, wherein the forwarding includesforwarding traffic to all of the plurality of tunnels concurrently. 10.A method implemented by an application executed by a mobile device, themethod comprising: establishing a plurality of tunnels to a gateway,wherein each of the plurality of tunnels is on one of a plurality oflink layer channels at the mobile device; intercepting network trafficon the mobile device; forwarding the network traffic to one of theplurality of tunnels based on a set of traffic forwarding rules; andresponsive to a network change for the mobile device, managing theplurality of tunnels and continuing the forwarding based on themanaging.
 11. The method of claim 10, further comprising determiningcharacteristics including bandwidth of each of the plurality of linklayer channels; and utilizing the characteristics with the set oftraffic forwarding rules for the forwarding.
 12. The method of claim 10,further comprising configuring the application with the set of trafficforwarding rules.
 13. The method of claim 10, wherein the set of trafficforwarding rules include a tuple of address or domain, assignedpriority, and address of the gateway.
 14. The method of claim 10,wherein each of the plurality of tunnels is a lightweight tunnel that isHypertext Transfer Protocol (HTTP)-based.
 15. The method of claim 10,wherein the intercepting is via one of a virtual interface and a networkfilter.
 16. The method of claim 10, wherein the plurality of link layerchannels include a wireless cellular channel and a Wi-Fi channel. 17.The method of claim 10, wherein the managing includes adding or removingtunnels based the network change.
 18. The method of claim 10, whereinthe forwarding includes forwarding traffic to all of the plurality oftunnels concurrently.
 19. A mobile device configured to execute anapplication for service discovery and connectivity, the mobile devicecomprising: a network interface, a data store, and a processorcommunicatively coupled to one another; and memory storingcomputer-executable instructions, and in response to execution by theprocessor, the computer-executable instructions cause the processor toestablish a plurality of tunnels to a gateway, wherein each of theplurality of tunnels is on one of a plurality of link layer channels atthe mobile device; intercept network traffic on the mobile device;forward the network traffic to one of the plurality of tunnels based ona set of traffic forwarding rules; and responsive to a network changefor the mobile device, manage the plurality of tunnels and continue theforwarding based on the managing.
 20. The mobile device of claim 19,wherein the computer-executable instructions further cause the processorto determine characteristics including bandwidth of each of theplurality of link layer channels; and utilize the characteristics withthe set of traffic forwarding rules for when the network traffic isforwarded.